In a conventional air conditioning apparatus or another air conditioning system, a vapor-compression refrigeration cycle is performed for circulating refrigerant in a refrigerant circuit having a compressor for compressing the refrigerant, a heat-source-side heat exchanger and usage-side heat exchanger for enabling the refrigerant to exchange heat, and a pressure-reducing mechanism for pressure-reducing the refrigerant. Among such air conditioning systems, there are those in which a plurality of indoor units including usage-side heat exchangers are disposed in the same large indoor space of, e.g., a conference hall or the like, in order to sufficiently condition the air in the same indoor space.
In an air conditioning system having a plurality of indoor units in this manner, e.g., the air conditioning apparatus disclosed in Japanese Laid-open Patent Application No. 2011-257126, operating efficiency is improved without causing the capabilities of the plurality of indoor units to be insufficient, by adjusting the operations of the outdoor unit and the plurality of indoor units.